Question

How does electronegativity affect polarity?

Answer 1

Well `"polarity"` is the degree of charge separation...

Explanation:

...whereas electronegativity is a measure of the ability of atom involved in a chemical bond to polarize electron density towards itself....

It follows that the GREATER the difference in electronegativities, the more polar the bond formed between the two elements.

We look at say `H-F`, and `H-Cl`, we gots Pauling electronegativities of `H=2.20`; `F=3.98`; `Cl=3.16`....

Because `Delta_"electronegativity"(H-F)">>"Delta_"electronegativity"(H-Cl)`..we would say that the `H-F` bond is more polar, more charge separated, that the `H-Cl` bond..